Microscopic Discontinuous Deformation of Structured Loess under Compression

ZHANG Jie; ZHANG Chang-liang; LI Ping; LI Tong-lu; QIAO Zhi-tian; LI Qiang

doi:10.11988/ckyyb.20200506

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Journal of Changjiang River Scientific Research Institute ›› 2021, Vol. 38 ›› Issue (5) : 123-130. DOI: 10.11988/ckyyb.20200506

ROCK-SOIL ENGINEERING

Microscopic Discontinuous Deformation of Structured Loess under Compression

ZHANG Jie^1,2, ZHANG Chang-liang¹, LI Ping^1,2, LI Tong-lu^1,2, QIAO Zhi-tian¹, LI Qiang¹

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Abstract

The structure of loess is closely related to its formation process and has an important impact on its physical and mechanical properties. In view of the large pores and cementation features of structured loess, we embedded the clay cementation which plays a major role in structured loess into the existing DDA. By using Monte Carlo method and DDA, we simulated the deposition process of loess, in particular, the collision and friction of particles in the falling process and analyzed the translational and rotational movements of particles in the consolidation process. On this basis, we constructed a microstructural loess model which is close to undisturbed loess in terms of void ratio. Furthermore, we simulated one-dimensional compression test on the structured loess model under different pressures with the extended DDA, and compared with indoor compression test to demonstrate the reliability of the numerical simulation. We found that, despite similar overall trends, the particle displacement of cemented sample was smaller than that of non-cemented sample. Vertical displacement of particles dominated regardless of some differences in the degree and direction of displacements. Major differences existed in different parts, i.e., upper particles underwent larger displacement, while lower particles witnessed smaller displacement.

Key words

structured loess / cementation / compression characteristics / microstructure model / DDA

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ZHANG Jie, ZHANG Chang-liang, LI Ping, LI Tong-lu, QIAO Zhi-tian, LI Qiang. Microscopic Discontinuous Deformation of Structured Loess under Compression[J]. Journal of Changjiang River Scientific Research Institute. 2021, 38(5): 123-130 https://doi.org/10.11988/ckyyb.20200506

References

[1] 雷祥义. 中国黄土的孔隙类型与湿陷性[J]. 中国科学:化学, 1987, 17(12):1309-1318.
[2] 赵景波.黄土的本质与形成模式[J].沉积学报,2003,21(2):198-204.
[3] 田堪良, 马俊, 李永红. 黄土结构性定量化参数的探讨[J].岩石力学与工程学报,2011,30(增刊1):3179-3184.
[4] 沈珠江.土体结构性的数学模型:21世纪土力学的核心问题[J].岩土工程学报,1996,18(1):95-97.
[5] 蒲毅彬, 陈万业, 廖全荣.陇东黄土湿陷过程的CT结构变化研究[J].岩土工程学报,2000,22(1):52-57.
[6] 雷胜友,唐文栋.黄土在受力和湿陷过程中微结构变化的CT扫描分析[J].岩石力学与工程学报,2004,23(24):4166-4169.
[7] 朱元青, 陈正汉. 研究黄土湿陷性的新方法[J].岩土工程学报,2008,30(4):524-528.
[8] 谷天峰, 王家鼎, 郭乐,等. 基于图像处理的Q₃黄土的微观结构变化研究[J].岩石力学与工程学报,2011,30(增刊1):3185-3192.
[9] 陈阳,李喜安,黄润秋,等.影响黄土湿陷性因素的微观试验研究[J].工程地质学报,2015,23(4):646-653.
[10] 郭培玺, 林绍忠. 粗粒料颗粒随机分布的数值模拟[J].raybet体育在线院报,2007,24(4):50-52,56.
[11] 郭培玺,林绍忠. 粗粒料力学特性的DDA数值模拟[J].raybet体育在线院报,2008,25(1):58-60,69.
[12] 张国新, 李广信, 郭瑞平. 不连续变形分析与土的应力应变关系[J].清华大学学报(自然科学版),2000,40(8):102-105.
[13] 郭龙骁, 张常亮, 杨德广等. 黄土单向压缩试验微观非连续变形分析[J].raybet体育在线院报,2017,34(3):80-84.
[14] GUO L, LI T, CHEN G, et al. A Method for Microscopic Unsaturated Soil-Water Interaction Analysis Based on DDA[J]. Computers and Geotechnics, 2019, 108: 143-151.
[15] 孙建中. 黄土湿陷的原因、因素与机制(理)[C]//中国工程建设标准化协会湿陷性黄土委员会全国黄土学术会议.兰州:中国建筑工业出版社,2001:146-151.
[16] SMALLEY I J, MARKOVI S B. Loessification and Hydroconsolidation: There is a Connection[J]. Catena, 2014, 117: 94-99.
[17] ROGERS C D F, DIJKSTRA T A, SMALLEY I J. Hydroconsolidation and Subsidence of Loess: Studies from China, Russia, North America and Europe: In Memory of Jan Sajgalik[J]. Engineering Geology, 1994, 37(2): 83-113.
[18] 王铁行,李彦龙,苏立君.黄土表面吸附结合水的类型和界限划分[J].岩土工程学报,2014,36(5):942-948.
[19] DERBYSHIRE E. Geological Hazards in Loess Terrain, with Particular Reference to the Loess Regions of China[J]. Earth-Science Reviews, 2001, 54(1/2/3):231-260.
[20] ROGERS C D F, SMALLEY I J. The Shape of Loess Particles[J]. The Science of Nature, 1993, 80(10): 461-462.
[21] DIBBEN S C,JEFFERSON I F,SMALLEY I J.The “Loughborough Loess” Monte Carlo Model of Soil Structure[J].Computers & Geosciences,1998,24(4):345-352.
[22] 张杰,李萍,李同录,等. 黄土沉积过程及微结构模型的非连续变形分析[J].工程地质学报.doi:10.13544/j.cnki.jeg.2019-517.
[23] HOOMANS B P B, KUIPERS J A M, BRIELS W J, et al. Discrete Particle Simulation of Bubble and Slug Formation in a Two-dimensional Gas-Fluidised Bed: A Hard-Sphere Approach[J]. Chemical Engineering Science, 1996, 51(1): 99-118.
[24] GB/T 50123—2019, 土工试验方法标准[S]. 北京:中国计划出版社,2019.
[25] TASHMAN L, MASAD E, PETERSON B, et al. Internal Structure Analysis of Asphalt Mixes to Improve the Simulation of Superpave Gyratory Compaction to Field Conditions (With Discussion)[J]. Maine Law Review, 2001, 61(1):490-498.